Nginx website with Ghost blog in a subdirectory sharing a single SSL

site.conf

server {

        root /var/www/html;
        index index.html index.htm index.nginx-debian.html;

        server_name domain.tld www.domain.tld;

        location ~ \.php$ {
                include snippets/fastcgi-php.conf;
                fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
        }

        location / {
                try_files $uri $uri.html $uri/ =404;
        }
        
        location ^~ /subdirectory {
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $http_host;
                proxy_set_header X-NginX-Proxy true;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_pass http://localhost:2368;
                proxy_redirect off;
        }


    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/snpranav.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/snpranav.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot


}